WASHINGTON, June 8 (Reuters) - Chinese government hackers who compromised the computers of a U.S. Navy contractor stole a large amount of highly sensitive data on undersea warfare, including plans for a supersonic anti-ship missile for use on U.S. submarines, the Washington Post reported on Friday, citing unnamed U.S. officials.

The breaches took place in January and February, the officials told the Post, speaking on condition of anonymity about an ongoing investigation. The hackers targeted a contractor who works for the Naval Undersea Warfare Center, a military entity based in Newport, Rhode Island, they said without identifying the contractor, according to the Post. (Reporting by Tim Ahmann; Writing by Eric Walsh)